INTESTINAL NUTRITION IN THE OPOSSUM 345 



the milk which shimmers through the body-wall as a large white 

 mass. In general, as in the embryo, the stomach lies in the 

 left side of the body with the greater curvature to the left and 

 the lesser curvature toward the right. Measuring the curvatures 

 again from the esophageal opening to the duodenum at its union 

 with the stomach, the ratio is about ten to one — showing an 

 increase in the greater curvature as compared with the ratio of 

 eight to one in the embryo. The esophagus and duodenum still 

 enter the stomach very close together; this striking nearness of 

 these openings into the stomach is a condition similar to that 

 described by Owen ('68) for the ornithorynchus. The inferior 

 border of the pyloric portion bulges below the duodenal opening 

 and above blends imperceptibly with the corpus. The organ 

 has expanded in all directions, but the greatest growth has been 

 in the lower part of the cardiac portion. The fundus does not 

 taper to a narrow tip and is much less conspicuous than in the 

 embryo. Especially as regards this part, the stomach is of the 

 simple carnivorous type seen in cat embryos. 



By its great expansion the stomach has altered the relations of 

 the other viscera; the small intestine has been crowded to the 

 right side; the lateral margins of the wolffian bodies have been 

 spread far apart; and the liver has been pushed upward and 

 flattened laterally, so that its greatest width is more than twice 

 its vertical thickness. Only a small portion of the stomach now 

 remains capped by the liver, as can be seen by comparison of 

 figures 6, 8, and 10. 



The rugae present in the gastric mucosa in the embryo have 

 become obliterated in the pouch-young, and except for a series 

 of slight plaited folds between the esophagus and duodenum, the 

 interior of the stomach, like the outside, has a smooth surface. 

 This smoothing of the mucosa may be accounted for by the 

 physiological distension of the organ with milk. The wall along 

 the greater curvature is much thinner than in the region of the 

 plaited folds referred to. The epithelium of the mucosa is made 

 up of cells of a low columnar type with large vesicular nuclei. 

 The cytoplasm is homogeneous and granular, being slightly more 

 condensed along the cuticular border. Just beneath this border 



